JPH0358856B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of operating an automatic production device, and can be used, for example, to improve setup work and processing accuracy in a machining center.

[Background technology and its problems] As a typical automatic production device, it is equipped with a tool change function and cuts a workpiece using a rotating tool.
A so-called machining center is known.

Conventional machining centers are based on the premise of so-called setup work, in which a tool of a certain diameter and its trajectory program are determined for each part of the workpiece to be machined after repeated trial cutting to the target finished dimensions of the workpiece. While the tools corresponding to each machining location are stored in a tool magazine, each trajectory program is sequentially arranged according to the machining procedure to create a machining program, and when one machining location is completed during operation, that machining program is used. Then, the tool and trajectory program adapted to the next machining location are switched to proceed to the next machining location, and after these steps are repeated in sequence, the series of steps is repeated for the next workpiece to achieve automatic production. It is.

Generally, the work processes in machining can be divided into a setup process and a cutting process. Machining centers can be seen as an improvement to the cutting process. In other words, as described above, once a certain workpiece is specified, a tool and a trajectory corresponding to it are automatically determined. This can be seen as a simple change in the cutting process, and therefore the setup process was essentially no different from that of a manual machine.

For example, when machining a certain hole, make a trial cut using a tool that seems to correspond to the target machining value, inspect the dimensions of the machined hole, and adjust the tool based on the inspection results. Then, test cutting is performed again and then re-inspected, and these steps are repeated in order to determine a tool with a specific diameter. At this time, in some cases, it may be necessary to prepare a plurality of identical tools in consideration of tool wear and damage. Further, in the case of outside cutting, in addition to the tool determination work, it is necessary to create a trajectory program for moving the tool and workpiece relative to each other. After such setup work and after storing one tool for each processing location in a tool magazine etc., the point at which the dimensions of the cut workpiece become outside of the tolerance due to the cutting process on the workpiece. Therefore, each tool or tool magazine was replaced.

However, the following problems are inherent in the setup work in such conventional machining centers. That is, an excessive amount of time was wasted on the tool selection work during the setup work. This is because, in most cases, adjustments based on inspection results after trial cutting are made back to the specialized manufacturer. In addition, from the perspective of eliminating the need for polishing, etc., a model with an adjustment means has been proposed, but
It is rarely used due to accuracy and economical issues.

The tool selection work during the setup work is largely based on experience, leading to a shortage of skilled workers, and variations among people, which is unfavorable in terms of accuracy.

Preparing the same tool required a great deal of cost and time.

During the above setup work, the machining center had to be maintained in that state until the adjusted tool arrived, which also hindered the actual operation of the cutting process. This is because if the machine starts operating before the adjustment tool arrives, the tool adjustment may become meaningless, mainly because the mechanical structural conditions will be different.

Due to these problems, conventional machining centers have had the remarkable effect of saving labor and making the cutting process unmanned, but the setup required a great deal of technical, time, and economic preparation. .

On the other hand, in terms of machining accuracy, there are many technical issues that must be solved in today's world where higher precision machining is required. One of the reasons is that the later a workpiece is machined, the larger the deviation from the target value, although it is still within the tolerance. This is because conventional machining centers are designed to replace the tool with a new one when the number of machining pieces and tool wear reach a predetermined value based on experience, or when the tool breaks.

In order to solve this problem, the idea arises that it would be better to replace the tool with a new one while the production quantity is relatively small, but as is clear from the setup work, it takes a long time to make adjustments because the tool is originally the same one. ,
This is not practical as it would impose a heavy financial burden.

Furthermore, a concept has arisen that it is sufficient to inspect the workpiece and change the tool trajectory after producing a certain quantity. However, this method requires a huge amount of time and effort and lacks practicality, as the trajectory program must be modified each time. Furthermore, even if this is possible, there is no guarantee that the error will be eliminated even if the vehicle is operated with a modified trajectory program.
This is because machining accuracy is determined as a combination of mechanical and electrical factors, so even if you change the command value of only the locus in the program (for example, the feed amount and direction of the tool or workpiece), it will not be the same as during pre-machining. This is because there is an inherent problem in that they are not necessarily processed with the same characteristics. Therefore, it can be said that it is not practical.

[Object of the Invention] Herein, the object of the present invention is to provide a method of operating an automatic production device that aims to improve processing accuracy and at the same time improve setup work without reducing productivity and workability as in the past. Our goal is to provide the following.

[Means and operations for solving the problems] Therefore, the present invention solves the above-mentioned problems of conventional machining centers in that one tool is specified for one machining location, and that the tool is used exclusively by skilled workers. Focusing on manual adjustment, we prepare multiple single tools of the same type with minute dimensions for one machining location in advance, and compare the measured value and target value (within tolerance and ideal) of the machined workpiece. A machining error (machining error that includes all factors of the machining center) is determined by comparing the machining center value), and based on this machining error, the tool to be used for the next workpiece is automatically selected from among the multiple single tools. Then, the next workpiece is processed.

Specifically, it includes a main body of a processing machine that cuts a workpiece using a rotary tool, a tool magazine that stores specific tools corresponding to each part of the workpiece to be machined, and one specific tool that is taken out from this tool magazine and used for the processing. A method of operating an automatic production device equipped with a tool changing means that can be attached to and removed from a machine body, and a control device that has a built-in machining program for operating these processing machine bodies according to a predetermined procedure, the method comprising: A specific tool preparation process in which a plurality of single tools of the same type and different dimensions are formed as a set and each set is stored in the tool magazine, and a measurement process to measure the dimensions, etc. of the workpiece machined by the processing machine main body. and an error determination step for determining a machining error by comparing the measured value measured in this measurement step with a preset machining target value, and based on the machining error determined in this error determination step, a tool selection step of selecting one single tool from among the specific tools;
a tool exchange process for replacing the single tool selected in this tool selection process with the single tool installed on the processing machine body and attaching it to the processing machine body, from the measurement process to the tool exchange process. The process is repeated sequentially, and based on the machining error of the previously machined workpiece, the single tool used for the next workpiece is automatically replaced to cut the next workpiece.

[Embodiment] FIG. 1 shows an embodiment of an automatic production apparatus that implements the method of the present invention. Broadly speaking, this device measures a machining unit 1 such as a machining center that processes a workpiece W, and a workpiece W machined by this machining unit 1, and selects a tool for the machining unit 1 based on the measurement results. It can be classified into a measuring section 3 that gives commands.

First, the processing section 1 includes a processing machine main body 11 that cuts a workpiece W using a rotary tool, and a processing machine main body 11 that cuts a workpiece W using a rotary tool.
A tool magazine 12 that accommodates a plurality of specific tools corresponding to each machining location, and this tool magazine 12
A tool changing device 13 as a tool changing means for taking out one specific tool specified from the processing machine body 11 and attaching and detaching it to the processing machine main body 11, and a tool changing device 13 as a tool changing means for taking out one specific tool designated from The control device 14 has a built-in machining program for operating according to the following procedures.

The processing machine main body 11 has a main shaft 16 that is movable in a three-dimensional direction, that is, in X, Y, and Z axes orthogonal to each other, with respect to a table 15 on which a workpiece W is placed, and that is rotatably driven around the Z axis. Prepare,
and the main shaft 16 receives a drive command from the control device 14.
It is designed to be moved in three-dimensional directions based on DC (x, y, z). The movement position of the main shaft 16 in the three-dimensional direction is detected by a position detector (not shown) (for example, an inductosin, a resolver, etc.), and then sent to the control device 14 as position data P (x, y, z). Feedback is being provided.

Further, as shown in FIG. 2, the tool magazine 12 includes an endless chain 20 that is wound around a plurality of sprockets (not shown), and this chain 20.
A plurality of tool pots 2 connected at regular intervals of
1, the chain 20 is driven according to a tool selection command from the control device 14 and the measuring section 3, and one of the designated tool pots 21 is moved to the tool change position TCP (a position facing the tool change device 13). and an indexing device 22 for positioning. In each of the tool pots 21, specific tools 23A, B, C, . Here, this work is referred to as a tool preparation process. Each of the specific tools 23A, B, C, . . . is configured as a set of a plurality of single tools of the same type that differ in diameter by a minute dimension within the tolerance of the machining location of the workpiece W to which the specific tool corresponds.

For example, when machining the workpiece W shown in Fig. 6, the hole H (target value 20φ, tolerance +0.1) is
Reamed with 3A, contour S (L ₁ = 150
mm, tolerance +0.1, L ₂ = 100mm, tolerance -0.1) with the specific tool 23B, the specific tool 23A
are four tools with different diameters of 1/100mm centered around the tolerance intermediate dimension (20.05φ) (tool diameter = 20.04φ, 20.05φ,
It consists of reamers 23A ₁ to 23A ₄ with diameters of 20.06φ, 20.07φ), and 5 specific tools 23B with diameters different by 1/100 mm (tool diameter d=20.00φ, 20.01φ,
20.02φ, 20.03φ, 20.04φ) end mill 23B ₁ ~
It is composed of _23B5 . Furthermore, regarding the other specific tools 23C and 23D, a plurality of single tools of the same kind differing in diameter by minute dimensions (for example, six drills 2
3C ₁ ~ 23C ₆ and 4 taps 23D ₁ ~ 23D ₄ , etc.)
Each is composed of Here, a group of single tools constituting one specific tool 23A, B, C, .

Further, the tool changing device 13 is configured to replace the single tool selected from the tool magazine 12 with the single tool attached to the main shaft 16 of the processing machine main body 11 and to attach it to the main shaft 16 of the processing machine main body 11. As shown in FIGS. 2 and 3, the drive device 32 is provided movably along a guide rail 31 in the same direction as the X-axis of the main shaft 16, and A turning shaft 33 is provided on the drive device 32 so as to be able to move up and down in the same direction as the Z-axis direction of the main shaft 16 and to be able to turn around the Z-axis.
and an arm 3 connected to the lower end of this pivot shaft 33.
It is composed of 4. Holding claws 35 are formed at both ends of the arm 34 to engage with a single tool housed in the tool magazine 12 and a single tool attached to the main shaft 16, respectively.

As a result, the tool changer 13 controls the control device 1.
Based on the tool selection command from 4, the drive device 32 moves to the tool magazine 12 side, holds the tool at the tool change position TCP in the holding claw 35 on the tool magazine 12 side, and then the drive device 32 moves to the tool magazine 12 side.
6 side, the tool attached to the main shaft 16 is held by the holding claw 35 on the main shaft 16 side, and then the arm 34 is lowered and rotated by the rotation shaft 33.
After being reversed 180 degrees, the tool taken out from the tool magazine 12 is held on the spindle 16. In this way, the single tool on the spindle 16 and the single tool on the tool magazine 12 are exchanged with each other by the operation of the tool exchanger 13.

In addition, the control device 14 stores a machining program for operating the machining machine main body 11 etc. according to a predetermined procedure, as well as various programs constituting the specific tools 23A, B, C, etc. stored in the tool magazine 12. For each single tool, a tool file list is provided that stores information about the tool, such as tool number, tool name, nominal diameter, material, tool length, etc.
A tool address list is provided for storing which tool pot 21 each single tool is housed in.

Next, a three-dimensional measuring machine 61 is used, which is responsible for the measurement process for measuring the dimensions, etc. of the workpiece W processed in the processing section 1, and the dimensions, etc. are calculated from the measurement data measured by this three-dimensional measuring machine 61. At the same time, an arithmetic processing unit 62 outputs a tool selection command to the tool magazine 12 of the processing section 1 based on the machining error with respect to the machining target value of the dimension, and a measured value of the dimension etc. obtained by the arithmetic processing unit 62. and a display storage device 63 for displaying and storing.

The three-dimensional measuring machine 61, as shown in FIG.
A column 73 is provided on both sides of the surface plate 71 on which the workpiece W is placed via guide rails 72 in the front-rear direction (Y-axis direction) with respect to the surface plate 71, and two slider guides are provided at the upper part between the two columns 73. A slider 75 moves in the left-right direction (X-axis direction) with respect to the surface plate 71 via a rail 74, and a spindle 77 having a touch signal probe 76 at the lower end of the slider 75 moves toward the surface plate 7.
1, respectively, so as to be movable in the vertical direction (Z-axis direction).

As a result, when the touch signal probe 76 is moved in the three-dimensional direction via the moving mechanism 78 consisting of the support 73, the slider 75, and the spindle 77, the position of the touch signal probe 76 in the X-axis direction is adjusted between the slider guide rail 74 and the slider. The position in the Y-axis direction is determined by the X-axis displacement detector 81 (see FIG. 5) provided between the guide rail 72 and the support column 73.
(see FIG. 5), and the position in the Z-axis direction is further detected by the Z-axis conversion detector 83 (see FIG. 5) provided between the slider 75 and the spindle 77, and then the arithmetic processing is performed. to device 62.

As shown in FIG. 5, the arithmetic processing unit 62 has a signal that is measured by the X, Y, and Z axis displacement detectors 81, 82, and 83 when the touch signal probe 76 is turned on due to contact with the workpiece W. A measurement data processing circuit 91 is provided to perform arithmetic processing on the measured data. The data processed by the measurement data processing circuit 91 is stored in the display storage device 63 and digitally displayed, while being supplied to the error discrimination circuit 92 which is responsible for the error discrimination process.

The error discrimination circuit 92 compares the data obtained by the measurement data processing circuit 91 with the machining target value stored in advance in the reference value storage circuit 93, and uses the machining error as a tool selection circuit 94 which is responsible for the tool selection process.
give to In the reference value storage circuit 93, a machining target value is preset for each machining location of the workpiece W. For example, in machining the workpiece W shown in Fig. 6,
Machining target value of hole H 20.05mm, machining target value of contour S
L ₁ =150.05mm and L ₂ =99.95mm are set in advance.

Further, the tool selection circuit 94 stores in advance the deviation of the tool diameter from the machining target value corresponding to the tool number of each tool stored in the tool magazine 12. The tool selection circuit 94 selects a tool number that cancels out the machining error based on the machining error given from the error discrimination circuit 92, and outputs the tool number to the tool magazine 1 via the output circuit 95.
Feedback to 2. This allows the tool magazine 12 to process the next workpiece W.
In a state where any specific tool is positioned in advance at the tool change position TCP according to a command from the control device 14, the single tool with the tool number selected by the tool selection circuit 94 among the specific tools is positioned at the tool change position TCP. Position it so that it comes to the right. the result,
The single tool positioned at the tool change position TCP is used for machining the next workpiece W.

Next, the operation of this embodiment will be explained. First, the workpiece W is placed on the table 15 of the processing machine main body 11 in the processing section 1.
When the control device 14 is started after the above setting, the main shaft 16 of the processing machine main body 11, the tool magazine 12, and the tool changer 13 are driven according to a machining program stored in the control device 14 in advance. For example, when reaming a hole H in a workpiece W, first the tool magazine 12 rotates to ream the hole H.
One of the specific tools 23A corresponding to the machining location, for example, the reamer 23A ₂ , is positioned to the tool change position TCP, and then the single tool 23
After A is attached to the main spindle 16 by the tool changer 13, the workpiece W is processed by movement of the main spindle 16. After finishing machining, tool magazine 12
As a result of the rotation, one of the specific tools 23B corresponding to the next machining location, that is, the contour S, for example, the end mill _23B3 , is positioned at the tool change position TCP, and then the single tool _23B3 is moved to the tool changer. After being attached to the main shaft 16 by 13, the workpiece W is processed by movement of the main shaft 16. In this way, multiple steps of machining are automatically performed on the workpiece W based on the machining program preset in the control device 14.

The dimensions of the workpiece W processed by the processing machine main body 11 are measured by the three-dimensional measuring machine 61 of the measuring section 3. To do this, after setting the workpiece W on the surface plate 71, the touch signal probe 76 is moved in a three-dimensional direction via the moving mechanism 78, and the workpiece W is set on the surface plate 71.
sequentially contact the machining points. Then, when the touch signal probe 76 is turned on due to contact with the workpiece W, the X, Y, and Z axis displacement detectors 81, 82,
83 data is taken into the measurement data processing circuit 91 of the arithmetic processing unit 62.

The measurement data processing circuit 91 determines the dimensions of the processed area from these data, and displays this on the display storage device 6.
3 is stored and digitally displayed, while being supplied to the error discrimination circuit 92. The error determination circuit 92 compares the data given from the measured data processing circuit 91 with the machining target value for each machining location preset in the reference value storage circuit 93, calculates the machining error, and calculates the machining error. It is applied to the selection circuit 94. The tool selection circuit 94 selects a tool number that reduces the machining error given by the error determination circuit 92 and supplies it to the tool magazine 12 via the output circuit 95.

For example, when machining a hole H in a workpiece W, a specific tool 23 is used.
Assuming that the actual measured value when machining using reamer _23A2 of A is 0.01 mm smaller in diameter than the machining target value, the tool selection circuit 94 determines that the machining error is set to a certain reference value (for example, between each single tool). If it exceeds the target value, reamer 23A ₃ with a diameter 0.01 mm larger than the processing target value.
is selected and the tool number is given to the tool magazine 12. As a result, when machining the next hole H in the workpiece W, the reamer _23A2 of the tool magazine 12 is first positioned to the tool change position TCP according to a command from the control device 14, and then the tool selection circuit 94
The reamer _23A3 is positioned to the tool exchange position TCP by the tool selection command from the reamer 23A3. Thereafter, the reamer 23A ₃ positioned at the tool change position TCP is attached to the main shaft 16 via the tool change device 13 and used for the next machining. In this way, based on the machining error with respect to the machining target value of the previously machined workpiece W, a single tool that reduces the machining error is used for machining the next workpiece W.

Therefore, according to this embodiment, the dimensions of the previously machined workpiece W are measured, the dimensions are compared with the machining target value of the relevant machining location, and the single tool with the diameter that reduces the machining error is selected as follows. Since the selection is made when machining the relevant machining location of the workpiece W, the control device 14
It is possible to perform machining close to target values without changing the machining program stored in the machine. This eliminates the need for time and effort associated with changing machining programs, and allows continuous operation without causing fluctuations in the mechanical and electrical characteristics of the machining center, which are determined by a variety of complex factors, eliminating machining errors. It is possible to process high-quality products with small dimensional variations regardless of the processing order.

This has the advantage of saving the effort of making corrections during machining in consideration of the amount of tool wear.

In addition, during setup work, there is no need to prepare a large number of tools with the same diameter as in the past, and there is no need to repeatedly perform trial cutting that requires hot kneading, making setup work quick and easy. Moreover, it is economical. Therefore, all of the above-mentioned problems, which were troublesome and inefficient when using a conventional machining center, can be solved. Moreover, the fact that there is no need to use tools of the same diameter has the advantage that even if each tool wears out during machining, it can be used for other machining locations.

Furthermore, as a result of feeding back the measurement results from the measuring section 3 to the processing section 1, completely unmanned operation is also possible. Moreover, as a feedback signal,
Since the tool number is selected by the arithmetic processing unit 62, it is easy to transmit and process signals, and there is an advantage that the equipment can be configured extremely simply.

In this embodiment, the processing section 1 has been described as a machining center, but it is equipped with a function to automatically exchange a plurality of tools with respect to the main shaft of the processing machine main body.
Any machine tool may be used as long as it can automatically control the movement locus of the spindle. In addition, the processing machine main body 1
1, the main axis 16 is not only in the three-dimensional direction but also in the Y direction.
It may be constructed so that it can be displaced in the vertical direction using the shaft as a fulcrum. Furthermore, although single tools are continuously stored in the tool magazine 12 for each specific tool, for example, a disk capable of storing a plurality of single tools is rotatably attached to the chain 20 of the tool magazine 12, and the same type of tools are stored on this disk. Each single tool is stored,
The disks of a specified tool group may be positioned at the tool exchange position by a command from the control device 14, and the angle of the disks may be determined by a command from the arithmetic processing device.

Further, the single tools of different dimensions constituting the specific tool are not limited to those with different diameters as described in the above embodiments, but may also be tools with different lengths, for example.

In addition to the manual three-dimensional measuring machine described in the above embodiment, the measuring machine body responsible for the measurement process may be one that automatically moves the touch signal probe 76 according to a preset trajectory program, for example. An automatic three-dimensional measuring machine may also be used. Further, while the support column 73 is fixed, the surface plate 71 is made movable in the Y-axis direction, and a plurality of touch signal probes suitable for each processing location of the workpiece W are set in advance on a part of the surface plate 71 in a detachable manner. Then, while automatically controlling the movement of the spindle 77 in the Z-axis direction, the slider 75 in the X-axis direction, and the surface plate 71 in the Y-axis direction, select one of the multiple touch signal probes. By using a three-dimensional measuring machine configured to select a probe suitable for the measurement location of the work W and automatically attach it to the spindle 77, all measurements of all processing locations can be performed automatically. In addition, the Tatsuchi Shinfu probe can be attached to the main shaft of not only a three-dimensional measuring machine but also a two-dimensional measuring machine or a machining center, and the configuration is such that the dimensions of the machined part of the workpiece W can be measured using the touch signal probe. It may be something you have done.

In addition, when selecting a single tool based on the machining error obtained from the measured value and the machining target value, it is limited to selecting a single tool with a diameter that reduces the machining error as described in the above example. First, for example, the order in which the single tools are used may be determined in advance, and when the machining error exceeds a certain range, the single tools may be selected in accordance with the determined order.

Further, in the above embodiment, the tool magazine 12 is driven by the tool selection command from the tool selection circuit 94, but the tool selection command from the tool selection circuit 94 is given to the control device 14, and the tool selection command from the control device 14 is driven. The tool magazine 12 may be driven by a command.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a method of operating an automatic production device that can perform highly accurate processing without reducing productivity and workability, and can improve setup work at the same time. can.

[Brief explanation of drawings]

The figures show an embodiment of automatic production equipment that implements the method of the present invention, in which Fig. 1 is a block diagram showing the overall configuration, Fig. 2 is a plan view showing an overview of the tool magazine, and Fig. 3 is a tool magazine. FIG. 4 is a perspective view showing the three-dimensional measuring machine; FIG. 5 is a block diagram showing the arithmetic processing device; and FIG. 6 is a diagram showing an example of processing a workpiece. . 11... Processing machine main body, 12... Tool magazine, 1
3... Tool changing device as tool changing means, 14...
Control device, 23A, B, C...Specific tool, 23A ₁
~23A ₄ ...Reamer as a single tool, 23B ₁ ~2
3B ₅ ... End mill as a single tool, 23C ₁ ~ 2
3C ₆ ...Drill as a single tool, 23D ₁ to 23D ₄
...Tap as a single tool.

Claims (1)

[Scope of Claims] 1. A processing machine main body that cuts a workpiece with a rotating tool, a tool magazine that stores specific tools corresponding to each processing location of the workpiece, and a machine that takes out one specific tool from this tool magazine. A method of operating an automatic production device comprising a tool changing means that is attached to and detached from the processing machine main body, and a control device containing a processing program for operating the processing machine main body etc. in a predetermined procedure, the method comprising: A specific tool preparation step in which tools are formed as a set of a plurality of single tools of the same type and different dimensions, and each set is stored in the tool magazine; and a step for measuring the dimensions, etc. of the workpiece machined by the processing machine body a measurement step; an error determination step for determining a machining error by comparing the measured value measured in this measurement step with a preset machining target value; a process selection process in which one single tool is selected from among the specific tools in the magazine; and a process selection process in which the single tool selected in this tool selection process is replaced with a single tool attached to the processing machine main body. a tool exchange process for mounting on the
The steps from the measurement process to the tool exchange process are repeated sequentially, and based on the machining error of the previously machined workpiece, the single tool used for the next workpiece is automatically exchanged to cut the next workpiece. A method of operating an automatic production device characterized by: